Equine Viral Encephalomyelitis
Equine Viral Encephalomyelitis is a disease which can be caused by several viruses (known as equine encephalitis viruses). Encephalomyelitis means inflammation of the brain and spinal cord. Equine viral encephalomyelitis can be fatal, although some animals will recover from the disease and mainly affects members of the equid family, such as horses, donkeys, mules, zebras. Other animals can also be affected, such as cattle, sheep and goats, pigs, birds, including poultry, dogs, rodents. Humans can also be affected.
If notifiable disease is suspected, contact DAERA on 0300 200 7840 or your local DAERA Direct Regional Office. Failure to do so is an offence
Current Situation
There has never been an outbreak of Equine Viral Encephalomyelitis in Northern Ireland.
Clinical Signs
Clinical signs can be different depending on which virus the animal has. Some animals will not show any signs at all.
You may spot these signs soon after infection:
- fever for several days
- lack of appetite
- loss of weight and condition
- depression
- stiffness and weakness
You may spot these signs in the later stages of infection:
- behavioural changes - such as circling, head pressing or aimless wandering
- hyperexcitability
- blindness
- lack of coordination and balance
- inability to move
- staggering or standing with an open stance
- seizures
What is the public health risk associated with this disease?
Humans can be infected by equine encephalitis viruses if they are bitten by an infected mosquito. Most people have no symptoms.
An infected person or horse cannot pass the virus directly to others. In rare cases, the virus can be spread during surgical interventions, such as a blood transfusion.
If your animal displays signs of infection and you are worried about your health, contact your GP for advice.
How is the disease transmitted?
The viruses that cause equine viral encephalomyelitis are mainly spread by mosquitoes. Other animals, including wild birds or rodents, can also carry the virus between different areas.
Only some types of mosquito can spread the virus. This means that if an infected horse did enter the UK, the possibility of the disease spreading would be low.
There has never been an outbreak of equine viral encephalomyelitis in the UK.
Prevention if Equine Viral Encephalomyelitis is Suspected or Confirmed in Northern Ireland
If you import animals, you must follow the rules to make sure they are free from disease and fit to travel.
You can help prevent the disease by:
- being familiar with the clinical sign of Equine Viral Encephalomyelitis
- practising strict biosecurity on your premises
If the disease is confirmed, the outbreak will be controlled in line with the contingency plan for exotic notifiable diseases.
Single Lifetime Identification Document for Equines (“Horse Passports”)
All equines in Northern Ireland need to have a Single Lifetime Identification Document (commonly referred to as a “horse passport”) to identify them.
Further information on how to obtain a horse passport.
More useful links
Venezuelan equine encephalitis - WOAH - World Organisation for Animal Health
British Horse Society: Equestrian Charity & Membership | The British Horse Society
International-Codes-of-Practice-2025_ITBA.pdf
HBLB International Codes of Practice | Home